I've been running the MSD-6BTM for the last three years on my supercharged 94. It retards timing based upon boost level. I have the base timing set to 9 degrees BTDC and pull out 1.25 degrees per lb. of boost. It works good for that purpose only. Will it do anything for a stock truck? I doubt it very much save your money. It seems that my plugs wear faster than they should but I don't know if that is ignition or supercharger related. The Irdium plugs go in this week.
I have an MSD RPM trigger to fire my Methanol/water injection. As PPC covered this is a purpose built device to acomplish something the OEM ignition doesn't do.
Unless you have a very special need, the OEM ignition components are difficult to improve upon.